The present invention generally relates to microelectronic power regulation systems. More particularly, the invention relates to a tiered power regulation system configured to supply high speed, high current power to a microelectronic device.
Microelectronic power regulation systems generally include a power regulator configured to supply a desired, regulated power to a microelectronic device such as microprocessors. The system may also include capacitors located near and/or packaged with the microprocessor to supply additional charge during the operation of the microprocessor. Such power regulation systems are configured so that the power regulator (e.g., a switching regulator such as a Buck regulator) provides nominal operating power to the microprocessor and the capacitors supply charge to compensate for transient power demands that result from operation of the microelectronic device. Such transient power demands may occur, for example, when several transistors of the microprocessor switch in the same direction at approximately the same timexe2x80x94e.g., when a portion of the device is powered off to conserve power or a portion of the device is activated.
As the speed and integration of microprocessors increase, the use of power regulation systems that only employ decoupling capacitors to compensate for or regulate transient power demands becomes increasingly problematic. In particular, the number and/or size of the capacitors required to account for transient events generally increases as the integration of the microprocessor increases. The capacitors take up a relatively large amount of space on the package and can be relatively expensive. In addition, as the speed and the performance of the microprocessor increases, the severity (e.g., the amplitude) of the transient power demands and the frequency of the events tend to increase. Capacitors within typical power regulation systems may be unable to adequately regulate such sever transient power demands. If not properly regulated, the transient power demands may cause noise on the power supply and induce errors during operation of the microprocessor. Accordingly, improved apparatus for responding to transient events that result during operation of a microprocessor are desired.
Furthermore, although typical Buck regulators are generally suitable for controlling power to some microprocessors, such regulators are not well suited to supply relatively high current (e.g., greater than about 30 amps) at relatively high speed (e.g., greater than about 500 MHz). One reason that Buck regulators have difficulty supplying high current at high speed to the microprocessor is that the regulator is configured to supply a single core operating voltage (Vcc) to the entire microprocessor. Supplying power from a single source and distributing the power to a limited number of locations of the microprocessor may be problematic in several regards. For example, various portions of the microprocessor may operate more efficiently at different amounts of powerxe2x80x94e.g. at different current and/or voltage levels. To compensate for the different power requirements, the microprocessor may require additional components and integration to step the power up or down as needed. Such additional components and integration may undesirably add to the cost and complexity of the microprocessor and systems including the microprocessor. Further, supplying all or most of the power from a single regulated power source requires a relatively large power regulator, which is generally inherently slow to respond to changes in power demands.
Another problem associated with supplying the same power to a limited number of locations of a microprocessor is that microprocessor wiring schemes configured to distribute the regulator power to the microprocessor are generally complex and include relatively long wiring sections to supply power to sections of the device located away from the input source of the power. The relatively long wiring sections may cause delay and undesirable signal degradation or loss of the transmitted power. Accordingly, improved methods and apparatus for providing power to a plurality of portions of a microelectronic device and to supply various amounts of power to a plurality of locations on the microprocessor are desired.
The present invention provides improved apparatus and techniques for regulating power to a microelectronic device. More particularly, the invention provides improved devices and methods suitable for supplying electronic devices with relatively high, regulated current at relatively high speed.
The way in which the present invention addresses the deficiencies of now-known regulators and power supply systems is discussed in greater detail below. However, in general, the present invention provides a power regulation system suitable for providing different power to a plurality of portions of a microelectronic device.
In accordance with one exemplary embodiment of the present invention, a power regulation system in accordance with the present invention includes a primary regulator configured to supply power and low-frequency transient suppression power to a plurality of locations on a microelectronic device. In accordance with one aspect of this embodiment, the power regulation system also includes a plurality of secondary or transient suppression regulators coupled to the primary regulator and the microelectronic device and configured to respond to or account for high-frequency transient power demands. In accordance with a further aspect of this embodiment, a secondary voltage regulator is configured in closed loop such that accurate voltage control may be obtained. In accordance with another aspect of the invention, a secondary regulators are configured in an open loop to quickly respond to the transient event. In accordance with another aspect of the invention, at least one secondary regulator includes both an open loop portion and a closed loop portion. In accordance with yet a further aspect of this embodiment, the power regulation system includes a controller coupled to the primary regulator to drive the primary regulator and adjust the operation of the primary regulator in response to or in anticipation of a transient power event.
In accordance with another embodiment of the invention, a power regulation system includes a plurality of primary regulators, wherein each primary regulator is coupled to a different portion of a microelectronic device. In accordance with one aspect of this embodiment, two or more of the plurality of regulators are configured to provide different levels of power to the different portions of the microelectronic device. In accordance with one aspect of this embodiment, the power regulation system also includes at least one transient suppression regulator coupled to at least one of the primary regulators and the microelectronic device. In accordance various aspects of the invention, the secondary regulators are configured in an open loop and/or closed loop topology. In accordance with yet a further aspect of this embodiment, the power regulation system includes a controller, configured to receive a signal indicative of a transient event, coupled to the primary regulator, such that the controller drives the primary regulator in response to the transient event.